that is correct it needed a little work with carbide rotor file so a tap will start and then tap it with a 5/16 -24 you don't even have to drill it this way I can start at an .080 hole and correct it from there as of to day I have install all the cam bearing 2,3,4 I have drill the oiling hole to 1/8 and I left #1 alone because I'm running the Milidon timing gear drive and I want the extra oil for the oiling of it